username = input("请输入手机号: ").strip()
password = input("请输入密码： ").strip()
code = input("请输入验证码： ").strip()

if username == "":
    print("手机号不能为空")
    if password == "":
        print("密码不能为空")
        if code == "":
            print("验证码不能为空")

            if len(username) != 11 or not (username.isdigit()):
                print("手机号格式不正确")
                if code.lower() != "8888":
                    print("验证码错误")
                    if username != "18776895770":
                        print("手机号不存在")
                        if password != "123456":
                            print("密码错误")
                            if username == "18776895770" and password == "123456" and code == "8888":
                                print("登入成功")

